.corewidth {
    width: 1200px;
}

.m-a {
    margin: 0 auto;
}

.fl {
    float: left;
}

.fr {
    float: right;
}

.clearfix:before,.clearfix:after {
    content: "";
    display: block;
    clear: both;
}

html,
body {
    color: #3a3a3a;
    font: 12px/1.5 "Helvetica Neue", Helvetica, Arial, "Microsoft Yahei", "Hiragino Sans GB", "Heiti SC", "WenQuanYi Micro Hei", sans-serif;
}